Acute kidney injury after primary total hip arthroplasty: a risk multiplier for complication, mortality, and healthcare utilization.

OBJECTIVE: To assess whether acute kidney injury (AKI) is associated with more complications and higher healthcare utilization in people undergoing primary total hip arthroplasty (THA). METHODS: Using a retrospective cohort study design, we performed multivariable-adjusted logistic regression of the 1998-2014 US National Inpatient Sample data to assess the association of AKI with complications (infection, transfusion, revision, and mortality) and healthcare utilization (total hospital charges, discharge to a rehabilitation facility, length of hospital stay) post-THA. We calculated the odds ratio (OR) and 95% confidence intervals (CI). RESULTS: Adjusted for age, gender, race, income, underlying diagnosis, medical comorbidity, and the insurance payer, AKI in people who underwent primary THA was associated with significantly higher OR (95% CI) of (1) implant infection, 2.34 (95% CI, 1.87, 2.93); (2) transfusion, 2.46 (95% CI, 2.37, 2.56); (3) revision, 2.54 (95% CI, 2.16, 2.98); (4) death, 8.52 (95% CI, 7.47, 9.73); (5) total hospital charges above the median, 2.29 (95% CI, 1.99, 2.65); (6) discharge to a rehabilitation facility, 2.11 (95% CI, 2.02, 2.20); and (7) hospital stay > 3 days, 4.34 (95% CI, 4.16, 4.53). CONCLUSION: Quality improvement initiatives with optimization of the peri-operative care to reduce AKI and subsequently AKI-associated complications and healthcare utilization are needed. Mechanisms of AKI-associated post-THA complications need further examination.